These core substantive rights include, most fundamentally, the opportunity of an individual to establish—with the person with whom the individual has chosen to share his or her life—an officially recognized and protected family possessing mutual rights and responsibilities and entitled to the same respect and dignity accorded a union traditionally designated as marriage.

What’s notable here is the starting point of the discussion: an “individual.” The individual citizen posited by the court is defined as prior to his or her sexual orientation. He or she exists as a person before he or she exists as straight or gay. And the right under discussion is defined as “the opportunity of an individual” to choose another “person” to “establish a family” in which reproduction and children are not necessary. And so the distinction between gay and straight is essentially abolished. For all the debate about the law in this decision, the debate about the terms under discussion has been close to nonexistent. And yet in many ways, these terms are at the core of the decision, and are the reason why it is such a watershed. The ruling, and the language it uses, represents the removal of the premise of the last generation in favor of a premise accepted as a given by the next.

The premise used to be that homosexuality was an activity, that gays were people who chose to behave badly; or, if they weren’t choosing to behave badly, were nonetheless suffering from a form of sickness or, in the words of the Vatican, an “objective disorder.” And so the question of whether to permit the acts and activities of such disordered individuals was a legitimate area of legislation and regulation.

But when gays are seen as the same as straights—as individuals; as normal, well-adjusted, human individuals—the argument changes altogether. The question becomes a matter of how we treat a minority with an involuntary, defining characteristic along the lines of gender or race. And when a generation came of age that did not merely grasp this intellectually, but knew it from their own lives and friends and family members, then the logic for full equality became irresistible.

This transformation in understanding happened organically. It began with the sexual revolution in the 1970s, and then came crashing into countless previously unaware families, as their sons and uncles and fathers died in vast numbers from AIDS in the 1980s and 1990s. It emerged as younger generations came out earlier and earlier, and as their peers came to see gay people as fellows and siblings, rather than as denizens of some distant and alien subculture. It happened as lesbian couples became parents and as gay soldiers challenged the discrimination against them. And it percolated up through the popular culture—from Will & Grace and Ellen to almost every reality show since The Real World.

What California’s court did, then, was not to recognize a new right to same-sex marriage. It was to acknowledge an emergent cultural consensus. And once that consensus had been accepted, the denial of the right to marry became, for many, a constitutional outrage. The right to marry, after all, is, as the court put it, “one of the basic, inalienable civil rights guaranteed to an individual.” Its denial was necessarily an outrage—and not merely an anomaly—because the right to marry has such deep and inalienable status in American constitutional law.

The political theorist Hannah Arendt, addressing the debate over miscegenation laws during the civil-rights movement of the 1950s, put it clearly enough:

The right to marry whoever one wishes is an elementary human right compared to which ‘the right to attend an integrated school, the right to sit where one pleases on a bus, the right to go into any hotel or recreation area or place of amusement, regardless of one’s skin or color or race’ are minor indeed. Even political rights, like the right to vote, and nearly all other rights enumerated in the Constitution, are secondary to the inalienable human rights to ‘life, liberty and the pursuit of happiness’ proclaimed in the Declaration of Independence; and to this category the right to home and marriage unquestionably belongs.

Note that Arendt put the right to marry before even the right to vote. And this is how many gay people of the next generation see it. Born into straight families and reared to see homosexuality as a form of difference, not disability, they naturally wonder why they would be excluded from the integral institution of their own families’ lives and history. They see this exclusion as unimaginable—as unimaginable as straight people would if they were told that they could not legally marry someone of their choosing. No other institution has an equivalent power to include people in their own familial narrative or civic history as deeply or as powerfully as civil marriage does. And the next generation see themselves as people first and gay second.

Born in a different era, I reached that conclusion through more pain and fear and self-loathing than my 20-something fellow homosexuals do today. But it was always clear to me nonetheless. It just never fully came home to me until I too got married.

It happened first when we told our families and friends of our intentions. Suddenly, they had a vocabulary to describe and understand our relationship. I was no longer my partner’s “friend” or “boyfriend”; I was his fiancé. Suddenly, everyone involved themselves in our love. They asked how I had proposed; they inquired when the wedding would be; my straight friends made jokes about marriage that simply included me as one of them. At that first post-engagement Christmas with my in-laws, I felt something shift. They had always been welcoming and supportive. But now I was family. I felt an end—a sudden, fateful end—to an emotional displacement I had experienced since childhood.

The wedding occurred last August in Massachusetts in front of a small group of family and close friends. And in that group, I suddenly realized, it was the heterosexuals who knew what to do, who guided the gay couple and our friends into the rituals and rites of family. Ours was not, we realized, a different institution, after all, and we were not different kinds of people. In the doing of it, it was the same as my sister’s wedding and we were the same as my sister and brother-in-law. The strange, bewildering emotions of the moment, the cake and reception, the distracted children and weeping mothers, the morning’s butterflies and the night’s drunkenness: this was not a gay marriage; it was a marriage.

And our families instantly and for the first time since our early childhood became not just institutions in which we were included, but institutions that we too owned and perpetuated. My sister spoke of her marriage as if it were interchangeable with my own, and my niece and nephew had no qualms in referring to my husband as their new uncle. The embossed invitations and the floral bouquets and the fear of fluffing our vows: in these tiny, bonding gestures of integration, we all came to see an alienating distinction become a unifying difference.

It was a moment that shifted a sense of our own identity within our psyches and even our souls. Once this happens, the law eventually follows. In California this spring, it did.

Andrew Sullivan was born in August 1963 in a small town in southern England. He attended Magdalen College, Oxford, where he took a first in modern history and modern languages. He was also president of the Oxford Union in his second year at college and spent his summer vacations as an actor in the National Youth Theatre of Great Britain.

In 1984, he won a Harkness Fellowship to Harvard's John F. Kennedy School of Government. In his summers, he interned as an editorial writer at The Daily Telegraph in London, and at the Centre For Policy Studies, Margaret Thatcher's informal think tank, where he wrote a policy paper on the environment, called "Greening The Tories." At Harvard, he was best known for acting, appearing as the title character in Hamlet, Alan in Peter Shaffer's Equus, and Mozart in Shaffer's Amadeus.

In the summer of 1986, after completing his master's degree in public administration, Andrew interned at The New Republic and wrote his first article for the magazine on the cult of bodybuilding. He then returned to Harvard to start a Ph.D. in political science. His doctoral thesis, "Intimations Pursued: The Voice of Practice in the Conversation of Michael Oakeshott," won the government department prize. In 1990, he returned to Washington, D.C., where he freelanced for The Telegraph and started a monthly column for Esquire. He was soon back at The New Republic as deputy editor under Hendrik Hertzberg, and in June of 1991, at the age of 27, was appointed acting editor. In October, he took over as editor, and presided over 250 issues of The New Republic. In those years, The New Republic's circulation grew to well over 100,000 and its advertising revenues grew by 76 percent. The magazine also won three National Magazine Awards for General Excellence, Reporting, and Public Interest. The first two awards overlapped with Rick Hertzberg's tenure at the magazine. In 1996, his final year at the magazine, Sullivan was named Editor of the Year by Adweek.

In the early 1990s, Sullivan became known for being openly homosexual, and for championing such issues as gays in the military and same-sex marriage. His 1995 book, Virtually Normal: An Argument About Homosexuality, became one of the best-selling books on gay rights and was translated into five languages. He followed it with a reader, Same-Sex Marriage: Pro and Con, and testified before Congress on the Defense of Marriage Act in 1996. His 1998 book, Love Undetectable: Notes on Friendship, Sex, and Survival, was a synthesis of three essays on the plague of AIDS, homosexuality and psycho-therapy, and the virtue of friendship. Sullivan tested positive for HIV in 1993 and remains in good health.

In the late 1990s, Sullivan worked as a contributing writer and columnist for The New York Times Magazine, a regular contributor to The New York Times Book Review, and a weekly columnist for The Sunday Times of London. His 2000 New York Times Magazine cover story on testosterone, "Why Men Are Different," provoked a flurry of controversy, as well as a cover-story in Time and a documentary on the Discovery channel. Since 2002, Sullivan has been a columnist for Time Magazine and a regular guest on HBO's Real Time with Bill Maher and NBC's Chris Matthews Show.

In the summer of 2000, Sullivan became one of the first mainstream journalists to experiment with blogging and soon developed a large online readership with andrewsullivan.com's Daily Dish. Andrew blogged independently and for Time.com and, in February 2007, moved his blog to TheAtlantic.com (archives here), where he was a senior editor for the magazine. In April 2010, Andrew moved to TheDailyBeast.com.